Turning the Konrad Mineshaft into a Safe Repository for Nuclear Waste

The former Konrad iron ore mine is located near Salzgitter, Lower Saxony, in Germany. After iron ore extraction ceased in 1976, experts studied the former pit’s geological suitability as a repository for low to intermediate-level radioactive waste. An approval procedure followed, which took years to complete before the pit could be converted into a repository. The current mine consists of six levels at around a hundred metres vertical distance from one another at depths ranging from 800 to 1,300 m.

Our expertise in shaft construc­tion, numerics and structural engineering earned us the job of planning, 3D numerical calculation and geological consul­ta­tion in the underground parts of the mine crucial to the project – storage location, workshops, backfill processing and transport routes.

Tunnelling and shoring work has begun in 2012. This involves first preparing the infra­struc­ture required for trans­port­ing and storing of radioactive waste containers at depths of 850 m on level 2. The existing shaft 2, at a depth of around 998 m, was remediated and an existing cross-cut near the second level was developed into a new storage location. This creates a 12.5 m cross-section, and existing spaces next to the pit are to be subse­quently extended. In addition, the repository will require new transport routes and spaces to be excavated for the workshop complex and backfill processing. The excavation work will be carried out mechan­i­cally while minimising inter­fer­ence with the mountain structure. 

In the long term, up to 303,000 m³ of radioactive waste with negligible heat generation are to be stored in the Konrad repository.